Apparatus for extracting gelatin and glue



Se t. 24, 1940. w v KNOLL I 2,215,528

APPARATUS FOR EXTRACTING' GELATIN AND GLUE Filed June 29. 1958 2 Sheets-Sheet l P 1940- w. v. KNOLL v APPARATUS FDR EXTRACTING GELATIN AND GLUE Filed June 29, 1938 2 Sheets-Sheet 2 Patented Sept. 24, 1940 UNITED STATES PATENT OFFICE 2,215,528 4 APPARATUS FOR nx'mao'rme GELATIN 7 AND GLUE This invention relates particularly to an apparatus for liberating gelatin and grease from animal matter such as hides and hide trimmings,

- sheep pates, bones, horn piths, etc., but is appli- 5 cable also in the reduction of fishery offal, and in the liberation and separation of oils and other by-products from vegetable matter such as soy beans, castor beans, nuts; and kindred vegetable growth. 7 I s :In the manufacture ofgelatin and glue, its liberation from the aforesaid raw materials is accomplished by cooking the materials, which have previously been washed and treated, in water at a comparatively low temperature, and while this operation is known in the industry as the boiling operation, the temperature at which it is carried out is seldom as high as the boiling point of water ranging instead from one hundred thirty to two hundred degrees Fahrenheit.

.the boiling operation, particularly the hides and trimmings, it is the conventional practice to.

place the materials into pits or concrete tanks, where a cover of approximately a two percent milk of lime solution is applied and left on for a period of-four to twelve weeks. Where packer's salted hide trimmings are being prepared, they are given a preliminary washing to remove dirt and salt, before being placed in the liming pit. Bone is given a preliminary treatment which comprises crushing and degreasing and subsequent maceration for extraction of the mineral substance by means of diluted acid, thereby producing a by-product acidphosphate.

To shorten the time of preparation for the boiling operation, the more drastic method of applying caustic soda is sometimes employed, but when this chemical is used, great care and attention must be given to prevent overtreatment. In any event, after the stock has been properly limed, which may be in some degree evidenced by the swollen condition of, the material, it is removed from the liming pit and placed in open washers, such washers generally comprising round wooden tanks set into a wash room floor. Usually a cone shaped roller is attached to a vertical post in the center, of the tank and made to roll in a circular path over the top of the stock being washed, squeezing and rubbing out the lime.

' The washing operation requires from ten to seventeen hours, until a titration test indicates that the alka'linity of the wash water ,has been reduced to-a' factor of 0.1. At this point, sul- 65 In the preparation of these raw materials for phuric acid is added to the stock as a neutralizer,

and after being subjected to the acid treatment for a period of as long as eight hours, the stock is againwashed until it is but slightly on the acid side. This'completes the preparation for the boiling operation.

While a number of improved devices have been proposed to facilitate the boiling operation, the industry in general still employs rather crude apparatus for this purpose. The most commonly employed apparatus comprises an open wooden 10 vat having a steam-coil resting on the bottom. In some cases heat is transferred to the material being'cooked by allowing steam to escape through small leakage holes in the steam pipes and percolate through the mass.

More generally the steam coils are not provided with leakage holes but transfer the heat of the steam to the mass by conduction. In such cases the coils are covered by a layer of excelsior which is in turn covered by a plank floor upon which the mass of material rests. The floor is provided with cracks or perforations to permit circulation of the liquor about the coils.

The space in the vat "above the floor is substantially filled with the prepared animal matter, 26

enough soft water being added to cover the stock.

Steam is then turned into the heating coils .to bring the water to the desired temperature, which depends somewhat'on the kind of material being treated. v

Obviously, with a heating element at the bottom of an open top vat it is very diflicult to maintain a uniform temperature through so large a mass; although the maintaining of a uniform temperature is highly important in the production of a. high quality product. In these open type vats no means of agitation is provided, the operators merely: loosening up the mass at intervals by inserting long hand paddles whereby they lift a portion of the mass 40 near the bottom to the topand open up spaces into'which the warm liquor may penetrate. This means of agitation is slow and laborious and I rarely loosens up the mass uniformly, and consequently many parts of the material remain for hours before being reached by the heated liquor, whereby the boiling operation. is greatly prolonged. I

Certain grades of skins, such as sheep pates w for instance, may contain up to 22% of their m weight in soluble fat or tallow. Due to the low temperatures used, this fat is released slowly and rises to the top in small quantities during the entire cooking period, where it must be still contains a large percentage of the available grease or tallow, which is customarily removed in a filter press, or by subjecting the mass to a gasoline extraction process. Even after use of a filter press there usually remains in the stock from six to nine percent of the grease.

Obviously, with the use of the open vat used as above described, or any other equipment at present employed in the art, the cooking period is greatly prolonged, the labor involved considerably greater than it should be and the final results far from as effective as desirable. Further, the prolonged period for which a given volume of material must be cooked necessitates a large number of vats which necessarily require a large fioor space area.

The period required to dispose of a single vat full of stock is further prolonged because the residue, from which the liquor has been ex tracted, settles to the bottom and is then removed with shovels or forks, the vat being subsequently cleaned of the excelsior and solid matter then thoroughly washed before it may be used again. Several hours are added to the time consumed by these cleaning operations.

With certain kinds of gelatin or glue stock, it has been found unadvisable to liberate all of the available gelatin, glue and tallow in a single cooking operation. This is due to the fact that the lower the temperature maintained in the circulating liquor, the higher the quality of the gelatin reclaimed. Such low temperatures, however, do not liberate a very high percentage of the total available gelatin, with the result that treatment at higher temperatures must follow if substantially all of the available gelatin is to g be extracted.

These stocks are usually subjected to several cookings, fresh water being introduced in each instance. The liquors drawn off in the several cookings are designatetd as first run, second run, third run, and fourth run liquors the temperature being raised at each succeeding run a matter of 10 or more degrees. It is of course the aim of the manufacturer to recover as much of the available gelatin in the first cooking as possible, because the first run liquor will produce a product of the highest quality and of the greatest market value. Gelatin produced from second, third and fourth run liquors is of progressively darker shade and lower quality. Glue from these subsequent runs is of lower adhesive quality as well as of less transparency than that made from first run liquor.

It is therefore the practice to prolong the first or low cooking period, not necessarily for a fixed period of time, but long enough to allow the liquor to reach a density usually corresponding to four to sixpercent of the dry gelatin, whereupon .methodor apparatus which would reduce the liquor of the first cooking to a density sufficient to warrant elimination of the subsequent evapcrating operation, and do this in a greatly reduced period of time, with less labor and equipment and in less floor space, would be a valuable contribution to the art.

It is therefore an object of this invention to provide an apparatus which will greatly reduce the time consumed, the steam used, the labor expended, the amount of equipment needed and the fioor space required, for liberating a given amount of gelatin from a given quantity of stock.

Another object is to provide an apparatus which will liberate and remove substantially all of the grease content in the stock being treated, whereby subsequent pressing of the residue or subsequent gasoline treatment following the boiling operation is unnecessary.

Another object is to provide an apparatus whereby the heat necessary to the boiling opera- A further object is to provide means for pro ducing a more highly concentrated liquor in a given time and with a given temperature, to the end that a separate evaporating operation may be avoided and the produce thereby benefited.

Still another object is to provide apparatus adapted to greatly facilitate the removal of the residue thereby saving considerable time and hard labor.

Other objects and meritorious features of the invention will become apparent from a consideration of the following description, reference being made to the drawings, wherein,

Fig. 1 is a front elevation of an apparatus for carrying out my invention.

Fig. 2 is an end view taken from the left of Fig. 1, showing more particularly the gear drive mechanism.

Fig. 3 is an end view taken from the right of Fig. 1 showing more particularly the water feed mechanism.

Fig. 4 is a top plan view of the apparatus.

Fig. 5 is a transverse section taken at 5-5 of Fig. 1, showing the agitating means, the charging manholes and the residue removal outlets.

Fig. 6 is a transverse section, taken at 6-6 of Fig. '1, showing the steam jacket structure.

Like numerals refer to like parts throughout the several views.

, Construction Referring'now to'the drawings which are illustrative of one embodiment of my invention,

a stationary tank l0, having a bottom l2 of semicircular transver' e cross section, and end walls I4, is mounted on a plurality of short legs l6 which extend upwardly from a base Hi.

'The top of tank I0 is flanged outwardly as at 20 to facilitate making a low pressure joint with a transversely arcuate lid 22 having a similar flange 24. Flange 24 is adapted to rest on flange 20 and is secured thereto by bolts It. A gasket (not shown) may be inserted between the two fianges as a precaution against leakage therebetween.

nil

Secured to the outer curved surfaces of the tank bottom I2 by riveting, welding, or any sim- Y use may be selected and incorporated to maintain the desired temperature at a uniform value. The short legs I6 have their upper surfaces contoured to fit the curved surfaces of the steam jackets.

Intermediate the steam jackets 30 in the tank bottom I2 are the residue removal chutes 38 provided at their outer ends with flanges 30' to which are secured the chute covers 42 by the screws 44. Drain cocks-45 are provided to facilitate removal of the liquid residue without removing the solid matter. Liquor draw ofl pipes 41 and 89, controlled by valves 5| and 50 .enter the tank at a plurality of points. A conventional density responsive control valve (not shown) may be inserted in the line, said valve to open when the density of the liquor has reached a predetermined value.

At the extreme top in the lid 22 is formed a grease trap 46 which preferably may have a transparent panel or window 68 somewhere within its length, through which the contents in the trap may be observed. A grease draw-off pipe 50, controlled by valve 52, extends alongside said trap and communicates therewith at several points within its length as at d, St. A relief cock 55 is provided to permit air to escape when it is A desired to completely fill the tank with water.

Mounted to be revolved within the tank I0 is the cylinder 56 having end heads 58 to the inner face of which the flanges 60 of the journals 62 and 6B are secured. Packing glands 66 in the tank end walls I4, allow-the rotatable journals 62 and 64 to extend through and beyond the walls ltwithout leakage, Bearings 68 and I0 are rovided to rotatably support the journals, the bearings being supported on the stands I2 and I4 extending upwardly from the base I8. A large distributing pipe I6. perforated as at I8 (see Fig. 1) extends throughout the length of the cylinder, the ends of the pipe extending a short way into the journals 62 and to maintain a concentric relation between the pipe and cylinder. I

Several channel shaped screens 80 of V shaped cross section and perforated as at 82 extend longitudinally at circumferentially spaced intervals along the inner wal of the cylinder, the open sides of the V being joined to the cylinder by welding or other suitable means.

. A plurality of perforations (see Fig. 5)- extend through the several sections of the cylinder wall that are covered by the V shaped screens. Radial struts 86 and 81 may join the pipe I6 to the screens and cylinder, and, if provided, will perform the additional function of cutting through and loosening up the mass of stock as the cylinder revolves.'

Longitudinally spaced manholes 08 extend throughithe "cylinder wall and may preferably be located circumferentially intermediate the V shaped screens, and should be longitudinally -posi-, tioned in the same axially-transverse plane as the residue removal chutes 38. Drain plates 90 and 92 may preferably be welded to the cylinder wall 6 and should slope downwardly toward the man holes when the man holes are turned to the bottom over the chutes. Man hole covers 9! are secured over the man holes by the screws 93.

The journal 64 has a large central opening 94 extending throughout its length communicating at its inner end with the distributing pipe 16 and having at the outer end a rotatable sealing joint comprising a non-rotatable housing 96 with cover 98 into whichthe water supply pipe I00 .extends. Screws] 02 secure the cover to the housing.

Within the housing 96, a spherically faced collar I04 is press fitted to the journal 64 and a 'second spherically facedcollar I06 is splinedly mounted 0110 the journal so as to be axially slidable thereon.

The spring I08 urges the collar I06 axially toward the outer end of the journal. Two washers III! have spherical faces ground for a 'pressure tight joint with the sphericalfaces of the collars, whereby water under pressure may be .fed to the cylinder while it is under rotation. A

valve H2 is provided to control the water supply.

To the outer end of the journal 62 there is ad secured a sprocket Ild for rotating the cylinder. An electric motor H6 or other suitable power source is mounted on across member IIB of base I8. A speed reducing gear box I20 has its shaft I22 connected directlyto, the motor shaft IN. The outer end of the gear box shaft I22 has secured thereto the sprocket I26.

- A countershaft I28 rotatably supported in bearings I30 secured to the sides of stands I32 and 12 by screws I34, carries the sprockets I36 and m I30 the tooth pitch of which matches that of sprockets I28 and H6 respectively. Silent chains M0 and I42 drivably join the pairs of sprockets.

The combined reduction through the chain drives and gear box provide a great reduction in speed for the cylinder relative to that of the motor.

Operation Where the per diem volume of stock which it is desired to treat is limited, a single apparatus as hereinbefore described may serve to carry out the liming, washing, and acidulating as well as the boiling operation. It may be preferable, however, where the production volume justifles, to employ the hereinbefore described apparatus for carrying out the boiling operation only, and then providing a separate apparatus for the other operations, such separate apparatus being somewhat modified to better effect that particular purpose.

Where the herein described apparatus is em-' ployed for liming, the operation is begun by removing the lid. 22 and manhole covers III and filling the cylinder with the stock to be treated 7 when replacing the man hole covers and lid and '5 opening the relief cock 55. Water carrying about two percent lime in solution is then injected through the pipe I00 until the cylinder and all additional spaces within the tank' I0 arecompletely filled. .Water coming out at the cook 55 will show when the tank is full. The cook 55 is then closed and the cylinder kept rotating for about sixty hours, no steam being turned into the steam jackets after which the lime solution may be drawn off by the drain cocks 45. Obviously, 15

to have been reduced to a factor of 0.1.

the constant rotation of the cylinder and the rubbing action through the mass by the screens 80 and the struts 86 soon applies the lime solu-v tion to every part of the mass of stock. When it is recalled that as much as ninety days is sometimes required to complete the liming operation by conventional methods it is apparent that the time saved by using the present apparatus is considerable.-

The washing operation may be carried out by first closing the drain cocks and opening the relief cock 55, then introducing clean soft water by way of thepipe I00 through the perforated distributing pipe I6 until the cylinder is completely filled. The relief cock is closed and, after the cylinder has been rotated for about one hour, the drain cocks are opened while the cylinder is kept rotating for a further period with a constant flow of water in at the pipe I00 and out through'the drain cocks 45, rotation of the cylinder and flow of the water being continued until a titration test shows the alkalinity of the water Sulphuric acid is now introduced through the incoming water to neutralize the stock, the period being extended until the stock shows slightly on the acid side whereupon all water is drawn off. No steam is introduced during the washing and acidulating operation, and fresh cold water only is passed through the apparatus.

The boiling operation for which the apparatus is most particularly intended is preferably conducted as follows: With the cylinder substantially full of the limed, washed and acidulated stock, the man hole covers and residue chute covers securely bolted, the drain cocks closed and the relief cock open, fresh, soft water, preferably at a temperature somewhat below the desired cooking temperature, is brought in through the pipe I00 and into the cylinder through the perforations in the distributing pipe 16 until the relief cock shows full whereupon the'relief cock is closed. Steam at the desired temperature for first run boiling is then introduced into the jackets 30' through the pipes 32, the regulator provided being set to the temperature most suitable for the stock being treated. Power is now applied to rotate the cylinder.

As the stock is turned over and over within the cylinder, the. temperature of the liquid rises and begins to release the grease or tallow from the stock permitting it to flow up into the grease trap where it accumulates until the operators see it through window 48 and draw it off through pipe 50, by opening valve 52. The grease or tallow will continue to be thus liberated as long as any remains in the stock capable of being broken down by the temperature being applied. It is desirable to remove the grease'or tallow' from the gelatin liquor at the earliest possible moment.

When it is considered that there may be as much as several tons of stock in the cylinder at one time, it is obvious that, during cylinder rotation, the stock is continuously, by its own weight, being pressed against, and rubbed over, the V shaped screens, whereby the liberated products are forced into the V channels and out of the cylinder through the holes 84. During this time the struts 8B constantly pass through the mass and assist its movement in a manner to help the liquid to penetrate all parts thereof. ously this treatment will produce a highly concentrated gelatin bearing liquor in the space in the tank outside the cylinder in a much shorter Obvi-' cally and allow liquor to discharge and fresh water to follow in through pipe I00 until the. density is lowered sufliciently to close the valve.

The steam control is next set for a higher value to liberate the gelatin for second run liquor. When the density again reaches the desired value the automaticvalve will draw off the second run liquor, the same process of raising the heat in the steam jackets being subsequently repeated until all of the gelatin has been extracted as third run, fourth run, etc. Of course, the tests for density may be made manually and the valve 5| .or 53 or the cock 45 hand operated when the ,desired density has been reached to draw off the liquor, each run being made with fresh water and higher heat.

When all the grease and gelatin has been removed, the residue must be removed. This will best be accomplished by first removing the lid 22 then removing the man hole covers 9| and the chute covers 42 then revolving the cylinder with the man holes open. Part of theresidue will be deposited in the chutes at each revolution and may be helped out of the chutes with a rake.

When substantially all of the residue has been dumped into the chutes, the cylinder is stopped with the man holes over the chute openings and the cylinder may be thoroughly cleaned by injecting clean hot water through the perforated distributing pipe 1,6.

Inasmuch as the raw 'stock is confined in the cylinder and slowly but uniformly agitated and pressed and rubbed against the screens while under heat, rapid and thorough extraction of the gelatin and grease is effected, and because of the uniformity in the application of the heated liquor to the stock a greater volume of first run liquor is produced. The filling of the cylinder 'and the discharge of the residue is also facilitated by the peculiar construction of the apparatus.

Standard practice may 'be followed in some of the subsequent steps in completing the process of ,making gelatin and glue, .that is, the introduction of filters to clarify the liquor, subsequent operations to further concentrate the same, molding, gelling, drying, grinding, etc., these steps forming no part of the invention are not further described.

While a single embodiment of the invention has been disclosed to illustrate the principle thereof it will be understood that various modiflcations and exemplifications will come within the scope of the following claims.

I claim:

1. The combination, in apparatus of the character described, of a tank, an axially-horizontal hollow cylinder rotatable in said tank, circumferentially spaced longitudinally extending channel shaped screens within said cylinder having their open sides secured to the cylinder walls, said cylinder wall being perforated in those portions embraced by the said open sides, and a" distributing pipe coaxial with said cylinder extending lengthwise therethrough and having axial perforations throughout its length.

2. The combination, in apparatus-of the char- Y sides secured to the cylinder walls, said cylinder walls being perforated in that portion covered by said channels, a coaxial perforated distributing pipe extending through the cylinder and supported in its end walls anda series of struts having one end secured to the pipe and the other end to the bottoms of said channel screens.

3. Apparatus of the character described, comprising, in combination, a tank, a relatively close fitting cylinder rotatable within said tank, a coaxial perforated distributing pipe extending lengthwise through said cylinder, circumferentially spaced longitudinally extending channelled screens projecting from the cylinder wallsinwardly, said cylinder wall having perforations under said screens, covers secured over longitudinally spaced manholes in said cylinder wall between said screens, and other covers secured over residue discharge openings in the bottom of said tank located in the same axially-transverse plane as said manholes.

4. Apparatus of the character described, comprising, in combination, a tank, a close fittingcylinder rotatably supported in said tank, a coaxial perforated distributing pipe .extending lengthwise through said cylinder, circumferentially spaced longitudinally extending channel shaped screens projecting from the cylinder wall inwardly, said cylinder wall having small perforations under said screens, bracing members extending from said distributing pipe radially to said screens, said cylinder having large stock filler openings in its wall and said tank having large residue discharge openings in its bottom in the same axially-transverse plane as ,the filler openings. i

5. Ina gelatin cooker, a tank, means for applying heat to the contents of said tank, a horizontally. disposed cylinder revolvable in said tank. said cylinder having circumferentially spaced longitudinally extending rows of perforations in its walls, perforated channels secured to the inside of said walls over said rows of perforations for agitating the cylinder contents, a perforated distributing pipe centrally disposed within said cylinder, said cylinder having large filler openings in its walls and said tank having large discharge openings in its bottom adapted to communicate with said filler openings when they are turned toward the bottom, a grease trap in the top of the tank, grease draw ofi pipes extending from said trap, and a series of gelatin draw off pipes in the side of the tank at different heights from the bottom.

6. In a'gelatin cooker, a tank, a steam jacket for applying steam toheat said tank, a horizontal cylinder revolvable within said tank and fltting it relatively closely, perforated agitating members of V shaped cross section extending longitudinally along the inner walls of said cylinder at circumferentially spaced intervals with the open side of the V sectionsecured to the wall to rotate therewith, said cylinder having perforations under said members, a coaxial perforated distributing pipe anchored in the cylinder ends, radially extending agitating member joining the perforated distributing pipe and the perforated agitating members, manhole covers longitudinally spaced in the sides 'of the cylinder, residue discharge covers diametrically opposite the manhole tion, a tank, asteam jacket against the wall of said tank, a horizontal cylinder rotatable in said tank, journals at the ends of said cylinder, one

journal having an axial opening therethrough, power means secured to the other journal to rotate said cylinder, 'a perforated distributing pipe within said cylinder coaxial with said cylinderrand having its ends anchored in the cylinder ends, the one end ,communicating with the axial opening through said journal, a rotatable seal joint connecting the outer end of said journal to a stationary supply pipe to effect communication between said supply pipe and the axial opening through said journal, a series of circumferentially spaced longitudinally extending perforated channel members having the open sides of the channels secured to the cylinder walls, said cylinder walls being perforated in the spaces embraced by said channels, agitating struts extending from the distributing pipe to the channels and to the cylinder-walls, manhole covers secured over manholesdongitudinally spaced in said cylinder between said channels, laterally extending chutes in the bottom of-the tank in the same axially transverse plane as the manholes, a grease trap in the top of the tank, grease draw of! means extending from said trap, andgelatin draw off means at different heights in the sides of the tank.

- WILLIAM V. KNOLL. 

